U.S. patent number 6,241,743 [Application Number 09/476,096] was granted by the patent office on 2001-06-05 for anastomosis device and method.
This patent grant is currently assigned to Intellicardia, Inc.. Invention is credited to Howard R. Levin, David C. Lundmark.
United States Patent |
6,241,743 |
Levin , et al. |
June 5, 2001 |
Anastomosis device and method
Abstract
This is an implantable device intended generally for forming an
anastomosis between a lumen of the body and an intersecting graft
lumen. The device may be configured to form an anastomosis which is
entirely lined with live tissue, or it may be configured to form an
anastomosis with synthetic material defining at least a portion of
one of the intersecting lumens.
Inventors: |
Levin; Howard R. (Teaneck,
NJ), Lundmark; David C. (Palo Alto, CA) |
Assignee: |
Intellicardia, Inc. (New York,
NY)
|
Family
ID: |
26831942 |
Appl.
No.: |
09/476,096 |
Filed: |
January 3, 2000 |
Current U.S.
Class: |
606/153 |
Current CPC
Class: |
A61B
17/0643 (20130101); A61B 17/11 (20130101); A61B
17/064 (20130101); A61B 2017/00243 (20130101); A61B
2017/1107 (20130101); A61B 2017/1135 (20130101) |
Current International
Class: |
A61B
17/11 (20060101); A61B 17/064 (20060101); A61B
17/03 (20060101); A61B 17/00 (20060101); A61B
017/04 () |
Field of
Search: |
;606/153,155,154,148
;623/1,11,12 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Pawlik et al, Effects of Dimaprit, Prostacyclin, and Acetylcholine
on Renal Blood Flow and Function, Proceedings of the Society for
Experimental Biology and Medicine, 163, 344-349 (1980), pp.
344-349..
|
Primary Examiner: Jackson; Gary
Attorney, Agent or Firm: Nixon & Vanderhye P.C.
Parent Case Text
This application claims benefit to U.S. provisional application
serial No. 60/134,073 filed May 13, 1999.
Claims
What is claimed is:
1. An anastomosis device for joining the end of a tubular graft
having a graft lumen with a tissue wall having an interior side and
an exterior side comprising:
a. an implantable structural member having proximal and distal
structural member ends, a longitudinal axis, an outer structural
member surface, a structural member inner lumen, and at least two
radial extensions extending outward from said structural member
surface at the distal structural member end; and
b. an implantable fastener having proximal and distal fastener ends
and an inner fastener surface configured to slidably interface with
said outer structural member surface,
wherein said proximal end of said implantable structural member is
configured to attach to said end of said tubular graft and fluidly
connect said structural member lumen with said graft lumen,
wherein said at least two radial extensions are configured to bend
toward the outer structural member surface when said implantable
structural member is urged, distal structural member end first,
through an aperture in said tissue wall and to bend away from said
outer structural member surface to prevent said implantable
structural member from being removed from said aperture when said
implantable structural member is urged in a reverse direction,
and
wherein said implantable fastener is operable to be moved distally
along said outer structural member surface to reach a sustainable
position wherein said tissue wall and said end of said tubular
graft are retained in compression against each other between said
implantable fastener and said at least two radial extensions.
2. The anastomosis device of claim 1 wherein said inner fastener
surface and said outer structural member surface have threads, said
threads causing said implantable fastener to move along the
longitudinal axis of said implantable structural member as said
implantable fastener is rotated in relation to said implantable
structural member.
3. The anastomosis device of claim 1 wherein said inner fastener
surface and said outer structural member surface have
groove-locking undulatory interference geometries which allow said
implantable fastener to move along the longitudinal axis of said
implantable structural member after a threshold force is applied
along said longitudinal axis.
4. The anastomosis device of claim 1 wherein the proximal end of
said outer structural member surface comprises a compliant sew
ring, said compliant sew ring configured to enable a sutured
coupling between said end of said tubular graft and said proximal
end of said implantable structural member.
5. The anastomosis device of claim 1 wherein said proximal
structural member end has a porous region, said porous region
having a multitude of small apertures configured to allow limited
fluid contact between said structural member inner lumen and said
outer structural member surface.
6. The anastomosis device of claim 1 further comprising a compliant
load ring having a proximal surface, a distal surface, and an inner
lumen, said compliant load ring being configured to prevent
compressive stress concentrations between said implantable fastener
and said at least two extensions.
7. The anastomosis device of claim 1 further comprising a slidable
elongate trocar member having a proximal end and a distal
wall-piercing end, said slidable elongate trocar member being
slidably interfaced with the structural member inner lumen and
configured to create a hole in said tissue wall through which the
distal end of the implantable structural member may be urged.
8. The anastomosis device of claim 1 wherein the at least two
radial extensions have tissue side and lumen side surfaces, the
tissue side surfaces having extension pins designed to grasp the
interior side of said tissue wall when said tissue side surfaces
are urged against said tissue wall.
9. The anastomosis device of claim 1 wherein said implantable
structural member comprises an oxygen sensor, said oxygen sensor
being configured to monitor the oxygen content of fluids passing
through said structural member inner lumen.
10. The anastomosis device of claim 9 wherein said oxygen sensor
comprises a light source and a light sensor.
11. The anastomosis device of claim 1 wherein said implantable
structural member comprises a fluid flow sensor, said fluid flow
sensor being configured to monitor the flow of fluids through said
structural member inner lumen.
12. The anastomosis device of claim 11 wherein said fluid flow
sensor comprises a Doppler transducer.
13. The anastomosis device of claim 1 further comprising a radial
extension restraining member, said radial extension restraining
member being substantially tubular in shape and removably coupled
about said implantable structural member in a delivery
configuration wherein said at least two radial extensions are urged
against said structural member surface, said at least two radial
extensions being free to extend outward after said radial extension
restraining member has been pulled toward said proximal structural
member end and thereby uncoupled.
14. A method of using the anastomosis device of claim 1 comprising
the steps of delivering said implantable flow diversion device to a
desired location against said tissue wall, creating an aperture in
said tissue wall at the location of said side hole, passing said
distal structural member end through said tissue hole and said side
hole, and placing said tissue wall and said implantable flow
diversion device in compression between said implantable fastener
and said at least two extensions.
15. An anastomosis device for joining a tubular graft with a tissue
wall having an interior side and an exterior side comprising:
a. an insertion structure having a main shaft with proximal and
distal ends, and at least two radial extensions, said at least two
radial extensions comprising proximal and distal portions, the
proximal portions being coupled to the distal end of said tubular
graft, the distal portions being coupled to the tubular graft and
releasably coupled to the proximal portions;
b. a threadlike wall attachment member;
wherein said at least two radial extensions are configured to bend
toward said main shaft when a deployment construct, comprising said
insertion structure with said main shaft partially encapsulated by
said tubular graft and said tubular graft coupled to said distal
portions, is urged, main shaft distal end first, through an
aperture in said tissue wall from said external to said interior
side, and to bend away from said main shaft to prevent said
deployment construct from being removed from said small diameter
hole when main shaft is urged in a reverse direction,
and wherein said threadlike wall attachment member is attachable to
said at least two radial extensions in a configuration operable to
urge said radial extensions toward said lumen side of said tissue
wall, thus placing said tissue wall and said tubular graft in
compression against each other.
16. The anastomosis device of claim 15 wherein said threadlike wall
attachment member comprises a suture placed through said tissue
wall and around said at least two radial extensions.
17. The anastomosis device of claim 15 wherein each of said at
least two radial extensions further comprises a piercing projection
extending therefrom and being configured to pierce through said
tubular graft and said tissue wall and provide an eyelet to which
said threadlike wall attachment member may be coupled.
18. The anastomosis device of claim 15 wherein said at least two
radial extensions are coupled to said tubular graft using a
suture.
19. The anastomosis device of claim 17 further comprising an
external retention saddle configured to be releasably attached to
said tissue wall and said piercing projections by said threadlike
wall attachment member, said external retention component operating
to dissipate stress concentrations between said threadlike wall
attachment member and said tissue wall.
20. The anastomosis device of claim 19, wherein said external
retention saddle comprises a ringlike structure having a multitude
of apertures through which said piercing projections may be placed.
Description
TECHNICAL FIELD
The present invention relates to surgical devices for anastomosis
procedures requiring the union of luminal structures of the body,
such as blood vessels or bile ducts, and more particularly, relates
to coupling devices which eliminate the use of traditional suturing
techniques for coupling such vessels in surgical procedures.
BACKGROUND ART
Among the important and time consuming tasks in surgical procedures
is the anastomosis or joining of severed blood vessels, and the
success of a surgical procedure may depend on the degree of
circulation which is restored through such anastomosis.
Anastomosing of blood vessels is a tedious procedure, particularly
in blood vessels of small diameter including blood vessels less
than one mm. in diameter. Conventional blood vessel suturing
techniques are time consuming, extending the duration of a surgical
procedure and successful anastomosing of blood vessels is highly
dependent on the proper placement of sutures by the surgeon.
Similar difficulty is often encountered in anastomosing synthetic
tubular graft materials to existing vessels of the body.
Various methods and devices for performing an end-to-side
anastomosis are known within the art of surgery. Most of these
known methods are, however, time-consuming, and thus not suitable
for use when time is at a premium and a quiet field of operation is
needed, as for example in the case of coronary bypass
operations.
U.S. Pat. No. 4,624,255 discloses an anastomosis device wherein a
member, preferably in the form of a ring, has structure for
tethering the blood vessel portions thereto under radial stress
with the intima of the blood vessel portions opposed. During
surgery, the ring is disposed around an end of one of the severed
blood vessel portions, and the blood vessel portions are tethered
to the ring at least three spaced apart locations stressing the
blood vessel portions radially outward in several directions to
evert the intima and hold the intima of the two portions against
each other. To hold blood vessel portions in close proximity during
anastomosis, a pneumatic clamping device is provided which grips
the blood vessel portions with a force according to the fluid
pressure supplied thereto.
U.S. Pat. No. 4,523,592 discloses an anastomotic coupling device
wherein a pair of coupling disc members cooperate to couple two
vessels, one of the members having spaced apart hook members, and
the other member having receptor cavities aligned with said hook
members for locking the members together in a successful
anastomatic procedure with tissue everted and secure on said hook
members.
U.S. Pat. No. 4,366,819 discloses an anastomotic fitting for
coronary artery bypass graft surgery having an assembly of four
components including a cylindrical tube having at least one ring
flange locking indentation in an inflow end and a plurality of
locking ring grooves in an outflow end, a ring flange having a
central aperture and pluralities of long and short spikes, the long
spikes engaging in the locking indentation, with a graft engaged
therebetween, a fixation ring having a central aperture and a
plurality of spikes positioned about the aperture, and a locking
ring having an aperture with a plurality of locking ring ridges for
engagement with the locking ring grooves. At surgical implantation
an aortic wall having a hole therein engages between the ring
flange and the fixation ring and is held in position by the spikes
of the fixation ring, and the four components engage together
forming an integral anastomotic fitting.
U.S. Pat. No. 5,366,462 discloses a method of using a staple for
joining first and second blood vessels wherein a staple having an
open center is provided to staple the two vessels together. One end
of the first blood vessel is placed through the staple and then
pierced by an end of the staple. An opening in the side of the
second blood vessel is formed and the pierced end of the first
blood vessel is inserted into the hole. A second end of the staple
is then deflectively bent and pierces the outer wall of the second
vessel to staple the two vessels together.
U.S. Pat. No. 4,917,087 discloses devices, kits and methods for
non-suture end-to-end and end-to-side anastomosis of tubular tissue
members employing tubular connection members having clip retaining
elements comprising annular groove or flanges in the connection
members and spring clips which comprise a ring-shaped body with
separable opposed ends whereby a circular opening defined by the
body can be enlarged. The opposed ends have handling elements to
facilitate handling of the clips and separation of the opposed
ends.
It is a general object of the present invention to provide methods
and apparatus which simplify surgical anastomosis techniques and
which effect an anastomosis with substantial assurance of
patency.
SUMMARY OF THE INVENTION
This invention is an device and method for creating an anastomosis
between a body lumen and a intersecting graft lumen. Each
embodiment requires the action of extension members which may be
placed through a relatively-small hole and expanded in size to
facilitate formation of the anastomosis.
One variation of the inventive device includes an implantable
structural member having proximal and distal structural member
ends, a longitudinal axis, an outer structural member surface, a
structural member inner lumen, and at least two extensions
extending outward from the structural member surface at the distal
structural member end. The implantable structural member is
attachably interfaced with an implantable fastener having proximal
and distal fastener ends and an inner fastener surface. The inner
fastener surface has a configuration wherein it will attachably
interface with the outer structural member surface. The proximal
end of the implantable structural member, in turn, is configured to
attach to and become partially encapsulated by the tubular graft.
The at least two extensions are configured to bend against the
structural member surface when the implantable structural member is
urged, distal structural member end first, through a small diameter
hole in the tissue wall and to bend outwardly from the structural
member surface to prevent the implantable structural member from
being removed from the small diameter hole when the implantable
structural member is moved in a reverse direction. The implantable
fastener is configured to lock the implantable structural member
into a final implanted configuration so that the tissue wall is
compressed between the distal end of the implantable fastener and
the at least two extensions.
The invention includes a method for using such a device to form an
anastomosis.
In another variation of the inventive device, an insertion
structure having a main shaft, proximal and distal ends, and at
least two radial extensions, the at least two radial extensions
being coupled to the tubular graft and releasably coupled to the
main shaft, is configured to be coupled with a threadlike wall
attachment member in a configuration wherein the at least two
radial extensions are configured to bend toward the main shaft when
a deployment construct, comprising the insertion structure with the
main shaft partially encapsulated by the tubular graft and the
tubular graft releasably attached to the expandable implant, is
urged, main shaft distal end first, through a small diameter hole
in the tissue wall from the external to the interior side, and to
bend outwardly from the main shaft to prevent the deployment
construct from being removed from the small diameter hole when main
shaft is urged in a reverse direction, and wherein the threadlike
wail attachment member is attachable to the at least two radial
extensions from the external side of the tissue wall, the
threadlike wall attachment member operating to urge the radial
extensions toward the lumen side of the tissue wall, thus placing
the tissue wall and the tubular graft in compression against each
other.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a side view of a synthetic-lumen variation of the
inventive device.
FIG. 2 depicts a sectional side view of a live-lumen variation of
the inventive device.
FIG. 3A depicts a side view of a structural member of a
synthetic-lumen variation of the inventive device.
FIG. 3B depicts a cross sectional view of a variation of a radial
extension of a synthetic-lumen variation of the inventive
device.
FIG. 3C depicts a cross sectional view of a variation of a radial
extension of a synthetic-lumen variation of the inventive
device.
FIG. 3D depicts a side view of a structural member of a
synthetic-lumen variation of the inventive device.
FIG. 4 depicts a partial side view of a structural member of a
synthetic-lumen variation of the inventive device.
FIG. 5 depicts a partial side view of a structural member of a
synthetic-lumen variation of the inventive device.
FIG. 6 depicts an orthogonal view of an implantable fastener of a
synthetic-lumen variation of the inventive device.
FIG. 7 depicts an orthogonal view of a compliant washer member of a
synthetic-lumen variation of the inventive device.
FIG. 8 depicts a side view of a trocar designed for use with a
synthetic-lumen variation of the inventive device.
FIGS. 9A-9C depict partial bottom views of different variations of
a structural member of a synthetic-lumen variation of the inventive
device.
FIGS. 10A-10E depict a method for installing a synthetic-lumen
variation of the inventive device.
FIG. 11A depicts a side view of an insertion structure of a
live-lumen variation of the inventive device.
FIG. 11B depicts a partial side view of an insertion structure of a
live-lumen variation of the inventive device.
FIG. 11C depicts a partial side view of an insertion structure of a
live-lumen variation of the inventive device.
FIG. 11D depicts a partial side view of an insertion structure of a
live-lumen variation of the inventive device.
FIG. 11E depicts a partial side view of an insertion structure of a
live-lumen variation of the inventive device.
FIG. 11F depicts a partial side view of an insertion structure of a
live-lumen variation of the inventive device.
FIG. 11G depicts a partial side view of an insertion structure of a
live-lumen variation of the inventive device.
FIG. 11H depicts a partial side view of an insertion structure of a
live-lumen variation of the inventive device.
FIG. 11I depicts a partial side view of an insertion structure of a
live-lumen variation of the inventive device.
FIG. 12 depicts a top view of an external retention saddle for use
with a live-lumen variation of the inventive device.
FIGS. 13A-13F depict a method for installing a live-lumen variation
of the inventive device.
FIGS. 14A and 14B depict side views of two variations of the
inventive device having restraining members coupled thereto.
DETAILED DESCRIPTION OF THE INVENTION
This invention is a device and method for efficiently creating an
end-to-side anastomosis between the end of a tubular member and a
tissue wall of another member. The inventive device has two primary
variations: a synthetic-lumen variation and a live-lumen variation.
Each of these primary variations is based upon the same principles,
but uses different materials to accomplish the goal of fluidly
connecting the end of a tubular member with the wall of another
member. More specifically, the synthetic-lumen variation provides
an anastomosis wherein fluids passing between the tubular member
and the confines of the associated tissue wall through the
anastomosis junction encounter a lumen portion which is primarily
defined by an exposed layer of synthetic material such as a
polymer. In contrast, the live-lumen variation provides an
anastomosis wherein fluids passing between the lumen defined by the
tubular member and the confines of the associated tissue wall
interface with lumen-defining walls primarily comprised of live
tissue. An important common aspect of each variation is the use of
radially disposed extensions configured to collapse to a relatively
small diameter during a "push in" step of implantation and expand
to a relatively large diameter during a "pull out" step of
implantation, operating somewhat like the action of the structure
which supports the fabric of an umbrella.
Referring to FIGS. 1 and 2, side views of synthetic-lumen (1) and
live-lumen (2) anastomosis devices in final implantation
configurations are depicted. In FIG. 1, an end portion of a tubular
graft (6) is shown coupled approximately perpendicularly to a
tissue wall (4) using a fastener (42) and a synthetic structural
member (12) having radial extensions (14) to urge a portion of the
tissue wall (4) into compression between the fastener (42) and the
radial extensions (14), thus providing fixation for the synthetic
structural member (12) and associated tubular graft (6).
In FIG. 2, an end portion of a tubular graft (6), in this variation
a live tissue graft preferably comprised of human endothelial
tissue, is shown coupled to a tissue wall (4) using detached
insertion structure radial extension portions (96) which are
coupled to a circumferential exterior retention saddle (90) in a
manner wherein the tubular graft (6) and tissue wall (4) are
fixated in compression against each other.
FIGS. 3A and 3B depict variations of the synthetic structural
member (12) in greater detail. Referring to FIG. 3A, a side view of
a structural member (12) is shown. The structural member (12) is
generally tubular, defining a structural member inner lumen (56)
and having an outer surface which is configured to form a threaded
(16) or groove-locking (18) interface with the inner surface of a
fitted fastener. Groove-locking interfaces are well known in the
art of small, particular polymeric, fittings and are described in
publications such as U.S. Pat. No. 4,366,819 for similar uses.
Groove-locking interfaces generally comprise two matched surfaces
having parallel undulations formed therein, the surfaces being
forced against each other, say in an interference fit between a
ring and a shaft, wherein the surfaces may be moved in relation to
each other against the interference fit of the grooves after a
threshold shear force has been developed between the surfaces
against the longitudinal direction of the grooves in each surface,
and wherein the surfaces will remain interlocked if forces less
than the requisite threshold shear force are developed.
As shown in the drawing, a sew ring (24) may be coupled to the
outer surface of the structural member (12) to facilitate
attachment of a tubular graft member. The compliant sew ring (24),
preferably comprised of a compliant yet fracture-tough composite
material made from a polymeric foam reinforced by small diameter
polymeric fibers, is coupled to the structural member (12) using
adhesives or partial encapsulation as in the preferred
embodiment.
The structural member is preferably comprised of a synthetic
material, such as a polymer, which is biocompatible, may be
precisely formed and machined, and has a stiffness high enough to
prevent kinking and significant deformation under loads resulting
from installation and implantation. Most preferred is ultra-high
molecular weight polyethylene (UHMWPE). As shown in FIG. 3A, the
walls of the structural member (12) may be fitted with sensors or
sensor portions (20, 22) for monitoring parameters of adjacent
tissues, such as temperature, oxygen level, hematocrit level, or
flow rate. Such sensors or sensor portions may be coupled to the
structural member using adhesives, interference fit, encapsulation,
combinations of these, or other standard methods. Certain sensors,
such as blood oxygen monitoring sensors, may emit and detect light
within the lumen (56) to operate, and therefore may require direct
access to the lumen, or have only a lucent layer of material
between themselves and the tissues flowing within the lumen (56).
Such sensors may have conductive leads (21) which are configured to
transmit energy or signal information to and/or from other devices.
Suitable sensors, including oxygen sensors such as those comprising
a light emitting device, pressure sensors such as those comprising
a piezoelectric transducer or a crystalline silicon chip, fluid
flow sensors such as those based upon Doppler transducer theory,
hematocrit sensors, temperature sensors, heart electrical signal
sensors, biochemical sensors, pH level sensors, and blood
electrolyte sensors are further discussed in U.S. Patent
application for "Instrumented Stent", attorney docket number
3659-6, which is incorporated by reference in its entirety.
Internal leads (25) which electrically connect one portion of a
sensor (20) to another (22), as in the case of a light emitting
portion and a light detecting portion, may be encapsulated within
the material comprising the structural member (12). The structural
member may also define a side input lumen (23), preferably
configured to facilitate fluid couplement between the structural
member lumen (56) and a medicine reservoir of a medicine pump (not
shown), which may be implantable. Suitable medicine pumps are known
in the art and are described in references such as U.S. Pat. Nos.
5,820,589, 5,207,666, and 5,061,242.
The variation depicted in FIG. 3A may be coupled with the tubular
end of a synthetic or live graft. In the case of a live graft, it
may be desirable to have a porous region (26) at the end of the
structural member (12) through which a live graft could obtain
flow-based nutrition. In other words, live graft material such as
vein autograft or artery autograft is made tip of endothelial
tissue which receives necessary nutrition from surrounding fluids;
having a porous substrate material through which the endothelial
tissue could receive blood-based nutrients is preferred because it
may enhance the probability of live tissue sustenance. The pores of
the porous region (26) extend through the wall of the structural
member (12) around a particular circumferential surface of the
structural member (12), as shown in the figure; they do not form a
filter through which flows in the structural member (12) lumen must
pass.
Also shown in FIG. 3A are radial extensions (14), coupled to the
structural member (12) and configured to expand outwardly when not
loaded, as shown, to bend toward the structural member (12) when
loaded by forces resulting during a "push in" step of installation
as described below, and to bend outwardly to a maximum bending
position which is nearly perpendicular to the structural member
during a "pull out" step of installation, as described below. The
radial extensions (14), generally comprised of a flexible metal
such as titanium or nickel-titanium alloy, may be coupled to the
structural member (12) using adhesives, an interference fit wherein
a portion of the radial extension forms a ring around the
structural member, partial encapsulation, or other standard
manufacturing techniques. Preferably, spiralled portions (32) of
the radial extensions (14) are partially encapsulated by the
material which forms the structural member (12), as is shown in the
drawing. The encapsulated spiralling (32) results in a desirable
stiffening of the end of the preferably polymeric structural member
(12) and an interface between structural member (12) and radial
extension (14) which facilitates cantilevered bending of the radial
extensions (14) during installation and implantation of the device,
as described below. Also shown coupled to the depicted variation of
the radial extensions are extension pins (30), preferably comprised
of the same material as their radial extension substrate and
coupled thereto with welds, adhesive, or other standard techniques,
or formed from the same piece of material as the radial extension
(14) and plastically deformed upward, as in the depicted
variation.
Referring to FIGS. 3B and 3C, cross sectional side views of two
variations of a radial extension (14) are shown to illustrate
potential cross sectional geometries. FIG. 3B depicts a variation
of a radial extension (14) having a rectangular cross sectional
geometry. Due to its large tissue contact side surface area (15),
this geometry is preferred with relatively elastic tissue walls,
which are able to stretch and accommodate a relatively
large-diameter folded implant without need for a large-diameter
implantation aperture. FIG. 3C depicts another variation of a
radial extension (14) having a roughly circular cross sectional
geometry. This radial extension shape is preferred with relatively
inelastic tissue walls because many circular cross section radial
extensions, preferably more than six, may be closely urged against
the structural member (12) during implantation so a smaller
installation aperture is needed and tighter overall fit may result
while still facilitating a strong fixation due to the multitude of
radial extensions (14) available to place the tissue wall in
compression between a fastener (42) and the radial extensions
(14).
Referring to FIG. 3D, another variation of the inventive structural
member (12) is depicted having a structural member lumen (58)
geometrically configured to have an internal venturi shape
comprised two conical tapered regions (33) a venturi throat (35)
and a venturi input lumen (37) a the region of low pressure created
when fluids are forced through the venturi throat at high
velocities. The phenomena of high velocity and related low pressure
using similar geometries is well known in the art of fluid
mechanics, and is described in publications such as Fluid
Mechanics, Second Edition, by Frank M. White, McGraw Hill, 1986.
Also shown in the depicted variation are sensors or sensor portions
(20, 22) configured to measure parameters of fluids flowing within
the structural member lumen (58). The dimensions of the venturi
throat are preferably configured for the particular patients or
groups of patients, based upon the pressures available in the
vessel lumen and the viscosity of the blood of the individual. As
relatively high pressure is required upstream of the structural
member (12) to create significant flows in the venture input lumen
(37), the venturi variation may not be appropriate for all
patients, especially those at risk for vessel aneurysm. For such
patients, the input of fluids such as medicine or blood is
preferably augmented by a fluid pump.
Referring to FIG. 4, a partial cutaway side view of a variation of
the inventive structural member (12) is shown having a cantilever
support portion (34) which extends outward and is configured to
support the radial extension (14) as it is placed in cantilever
bending during installation and implantation, as described below. A
cantilever support portion is particularly useful to prevent
bucking of radial extension members (14) comprised of relatively
stiff materials, and to prevent over-bending (past the desired
maximum downward bending position which is approximately parallel
to the tissue wall against which the radial extension (14) is urged
during installation and implantation) of radial extension members
comprised of particularly flexible materials such as some
nickel-titanium alloys.
Referring to FIG. 5, a partial sectional side view of a variation
of the inventive structural member (12) is shown having a tapered
end region (36) which is configured to slide more easily through a
relatively small-diameter aperture created in a tissue wall upon
implantation, as described below. The angle of tapering of the
tapered end region (36) is generally configured to match that of a
trocar, depicted in FIG. 8 and described below, which may be used
to create a small aperture in the tissue wall (4) through which a
portion of the device is passed during implantation.
FIG. 6 shows an orthogonal view of a variation of the fastener (42)
designed to interface with the outer surface of the structural
member (12) and hold the tissue wall (4) in compression after
installation. The fastener is preferably comprised of similar
materials as the structural member (12), ultra-high molecular
weight polyethylene being most preferred. The fastener (42) has an
inner lumen (44) configured to interface with the outer surface of
the structural member. More particularly, the fastener is
configured to slide along the outer surface of the structural
member (12) with relative freedom, and to interface using threads
(16) or undulations(18) (for a groove-locking interface) with the
portion of the structural member (12) outer surface configured with
like geometric features. As shown in FIG. 6, the outer surface
geometry of the fastener (42) is configured to be easily
manipulated, or more particularly pressed downward, by the fingers
of a person conducting an installation. The bottom cross sectional
area (43) of the fastener (42) is large relative to the top cross
sectional area (45) to spread compressive loads generated at the
interface between the fastener (42) and the tissue wall (4) over a
larger surface area, as well as for ergonomic reasons.
Referring to FIG. 7, a compliant load ring (46) is shown in
orthogonal view. The compliant load ring (46) has an inner diameter
configured to slidably interface with the outer surface of the
structural member (12) and an outer diameter approximately equal to
that of the fastener (42). The compliant load ring (46), preferably
comprised of a relatively compliant biocompatible material such as
polyurethane or cotton felt, is designed to prevent localized
compressive stress concentrations which may occur between the
bottom surface of the fastener (43) and the associated tissue wall
(4) during installation and implantation.
FIG. 8 depicts a trocar (38) having a tapered distal end (40) which
is suitable for assisting in the installation of the inventive
device. The outer diameter of the trocar (38) is slightly smaller
than the structural member (12) inner lumen (56) diameter so the
trocar (38) may be slidably positioned within the lumen (56) and
then slidably removed after an aperture has been created in the
tissue wall (4) using the tapered distal end (40) of the trocar
(38).
Referring to FIGS. 9A-9C, partial bottom views of different
variations of a synthetic structural members (12) with radial
extensions (14) of a synthetic-lumen variation of the inventive
device are shown. FIG. 9A shows a variation having two radial
extensions (14). FIG. 9B shows a variation having three radial
extensions (14). FIG. 9C shows a variation having two radial
extensions (14). The number of radial extensions (14) required for
adequate device fixation depends upon the compliance of the tissue
wall (4) and the stress concentration which the tissue wall (4) can
withstand without being physiologically compromised. A variation
having at least three radial extensions (14) is preferred in
scenarios wherein the tissue wall comprises human endothelial
tissue such as healthy venous or arterial tissue of a large
vessel.
FIGS. 10A-10E depict a method for installing a synthetic-lumen
variation of the inventive device. As shown in FIG. 10A, the
structural member (12) is placed in contact with the tissue wall
(4) to be anastomosed. A trocar (38) is slidably mounted within the
structural member (12) lumen (56) having a tapered end (40) matched
to the tapered end portion (36) of the structural member (12). FIG.
10B shows a device (1) partially inserted into a tissue wall (4)
aperture (5). The trocar has been slidably removed and a removable
cap (54) placed upon the structural member (12) to prevent fluids
from flowing up and out of the structural member lumen (56). The
removable cap (54) is preferably comprised of an easily formable
and machinable polymer material with enough stiffness to snap into
place in a slight interference fit, such as ultra-high molecular
weight polyethylene, polyethylene, polypropylene, polybutylene, and
mixtures and copolymers thereof. The drawing shows the radial
extensions (14) being bent upward as the device is pushed through
the aperture (5) in the tissue wall (4). Also shown are a fastener
(42) and a compliant load ring (46) slidably interfaced with the
top portion of the structural member (12).
Referring to FIG. 10C, the device construct shown in FIG. 10B has
been advanced further downward into the confines of the tissue wall
(4). As shown in the drawing, the radial extensions (14) are bent
into a configuration wherein they are pressed nearly flush against
the structural member (12) as the device is pressed, or "pushed
in", through the aperture (5) in the tissue wall (4).
FIG. 10D shows the device advanced to a depth within the confines
of the tissue wall (4) at which the radial extensions (14) are able
to spring back to their unloaded position, as shown in the drawing.
In this configuration, the device has been pushed in as far as is
necessary for proper installation.
FIG. 10E depicts the device after the structural member (12) has
been pulled in a reverse direction, or "pulled out", into a
configuration as shown wherein the radial extensions (14) are urged
against the tissue wall (4) and forced into cantilever bending. The
position is retained after the fastener (42), shown in side view,
has been pushed down and locked into place against the compliant
load ring (46) using threads or groove-locking, thus placing the
tissue wall (4) into compression between the compliant load ring
(46) and the radial extensions (14). Also shown in the figure is a
graft member (6) coupled to the structural member (12) after
removal of the removable cap (54), in this example via stitches
through a sew ring (24) attached to the top of the structural
member (12).
Referring to FIGS. 11A-11I, various partial side views and partial
orthogonal views of a live-lumen variation of the inventive device
are depicted.
FIG. 11A depicts a partial side view of a live-lumen insertion
structure (60). As shown in the figure, an insertion structure main
shaft (70) is coupled to at least two radial extensions (64). The
ends of the radial extensions (64) are configured to attach to the
ends of a live tubular graft member.
In the depicted embodiment, the ends of the radial extensions (64)
comprise radial extension graft connection portions (76) configured
to facilitate coupling between a graft and radial extensions (64)
using a suture (not shown). The radial extensions (64) are
preferably comprised of a flexible material, such as a
nickel-titanium alloy, which is capable of withstanding significant
bending without structural failure or plastic deformation. To
facilitate cantilevered load bearing by the radial extensions (64)
they are fixedly coupled to the main shaft (70) of the insertion
structure (60) using adhesives, encapsulation, or other known
techniques. In the depicted variation, the ends of the radial
extensions (64) are encapsulated by the material forming the main
shaft (70) in a spiral fashion (66); the spiralling is better shown
in FIG. 3A for another variation of the inventive device. The
radial extensions (64) may have shapes and configurations similar
to those shown for the synthetic-lumen variation of the inventive
device in FIGS. 9A-9C and 3C-3D.
The main shaft of this variation is designed to be detachable from
the ends of the radial extensions because leaving it in place after
the anastomosis is formed would be leaving a large mass at the
middle of the flow path for blood moving through the anastomosis--a
potential thrombogeneity risk problem. In other words, a clot could
form at upon the mass due to the concentrated flow, and could later
be thrown off into the circulatory system. Therefore it is
desirable to leave a clear flow path within the anastomosis, and
thus the main shaft is removable. FIG. 11A depicts both a release
lead (68) and a pull wire (86). The release lead (68) is depicted
to demonstrate that the main shaft (70) or a portion thereof may be
configured to conduct electricity between a power source (not
shown) and an electrolytic detachment zone (82) designed to erode
upon application of electric current. The pull wire (86) is
depicted to illustrate that portions of the radial extensions (64)
may be mechanically detachable through actuation of a pull wire
(86) which uncouples a detachable portion when pulled outward, the
pull wire (86) being configured to have an arcuate path through the
main shaft (70) of the insertion structure (60) to minimize
friction between the materials comprising the main shaft (70) and
the pull wire (86).
Also depicted in the variation of FIG. 11A is a insertion structure
lumen (62) configured to facilitate use of a trocar (not shown)
which may slidably engage the walls of the insertion structure (60)
defining the lumen (62). Many suitable trocars with approximately
cylindrical cross sectional geometries and pointed tips are known
in the art. The figure also illustrates that sew posts (72) are
coupled to the radial extensions (64) and configured to push
through the tissue wall into which they are forced during
installation of the device.
Referring to FIG. 11B, a close-up side view of a variation of a
radial extension (64) is shown having a sharpened sew post (72) and
a small eyelet as a graft connection portion (76), the small
eyelets being configured to accept a suture configured to couple a
graft end to the radial extensions (64). The sharpened sew posts
(72) are termed "sew posts" because they are configured to accept a
suture. This figure, as well as FIGS. 11C, 11D, and 11E, each a
close up side view of a radial extension (64) variation, illustrate
that the radial extension (64) has a dislocation region (80) which
may comprise an erodable link (82) or a mechanically detachable
link (84).
Suitable erodable links are disclosed in references such as U.S.
Pat. Nos. 5,354,295, 5,122,136, 5,891,128, 5,423,829, and
5,624,449. Suitable mechanically-detachable links are disclosed in
references such as U.S. Pat. Nos. 5,304,195 and 5,250,071.
Referring to FIGS. 11F and 11G, close-up end and side views,
respectively, are shown of a variation of the inventive radial
extension (64) specifically showing details of a sew post (72)
variation. The sew post (72) preferably has a sharpened tip and a
multitude of apertures (74) configured to accommodate sutures
therethrough during installation of the device. The sew posts (72)
of this variation are welded in place upon the substrate metal
material which forms this variation of radial extensions (64).
Referring to FIGS. 11H and 11I, close-up side and end views,
respectively, of a variation of the inventive radial extension (64)
are shown. These figures depict a similar sew post (72) geometry as
that of the previous figures, with the exception that the sew posts
(72) depicted in FIGS. 11H and 11I are formed from the same piece
of material which comprises the substrate radial extensions (64).
Preferably they are bent up into position like splinters or wedges
of the material after apertures (74) have been formed in the
material. Also depicted in FIG. 11H is a graft connection portion
(76), in this variation taking the form of a small eyelet formed in
the material of the radial extensions (64) which is configured to
facilitate suturing between the radial extension (64) and a graft
end (not shown).
Referring to FIG. 12, an external retention saddle (90) is depicted
in top view. The external retention saddle (90) is designed to
interface with the tissue wall and distribute compressive loads to
the tissues forming the tissue wall which result during and after
installation of the device. The external retention saddle (90) is
termed a "saddle" because of the shape it is capable for forming
around the circumference of a hole in the side of a roughly
cylindrical vessel. The external retention saddle (90) has a
multitude of apertures (92) which are configured to interface with
sew posts (not shown) which are configured to protrude through the
tissue wall from the other side of the tissue wall. The apertures
(92) of the external retention saddle may vary in geometry,
depending upon the shape of the interfacing sew posts. The depicted
embodiment has some roughly circular apertures (92) and some
roughly rectangular apertures (93). The external retention saddle
(90) is preferably comprised of a flexible biocompatible material,
such as polyethylene or polyurethane, which may be precisely formed
and is flexible enough to deform to saddle-like geometric
configurations while being tough enough to distribute loads without
fracturing.
Referring to FIGS. 13A-13F, a method for installing a live-lumen
variation of the inventive device is depicted.
FIG. 13A shows a insertion structure (60) with a main shaft (70)
having tapered ends (69) interfaced with a tissue wall (4) and
slidably engaged with a trocar (38). Radial extensions (64) with
sew posts (72) extending therefrom are shown in an unloaded
position, coupled (76) with a live tissue graft member (10) by a
suture (78). To facilitate insertion through a relatively-small
aperture, the tapered ends (69) of the insertion structure (60)
main shaft (70) have tapers which roughly match those of the trocar
(38), as shown in the figure.
Referring to FIG. 13B, the trocar (38) and insertion structure (60)
are urged through the tissue wall (4), causing the radial
extensions (64) to be bent upward toward the main shaft (70) of the
insertion structure (60). The trocar (38) is then removed and the
insertion structure (60) pulled upwards, as is shown in FIG. 13C.
FIG. 13C also shows that the graft member (10) is stretched outward
as the insertion structure (60) is pulled upward, because the
radial extensions (64), coupled (76) to the graft member by a
suture (78), bend outwardly as they are urged toward the tissue
wall (4).
Referring to FIG. 13D, the insertion structure (60) is pulled
upwards until the sharp-tipped sew posts (72) have been urged
through both the graft member (10) and the tissue wall (4). The
figure also depicts the location of the radial extension
dislocation regions (80) of the radial extensions (64). FIG. 13E
depicts the use of a blunt-end tool (94) to apply localized
compression to the graft member (10) and tissue wall (4) by
pressing down on a portion of a hand-placed external retention
saddle as the insertion structure (60) is pulled upwards. This
localized compression exposes a greater portion of the protruding
sew post (72) and enables a suture to be passed through an aperture
(74) in the sew post which will result in the proper compressive
load upon the graft member (10) and tissue wall (4) which can be
better distributed by the increased surface area of the external
retention saddle (90).
As shown in FIG. 13F, after the external retention saddle has been
completely installed via sutures (78) through sew post (72)
apertures (74) circumferentially located about the anastomosis
site, the upward load upon the the insertion structure (60) main
shaft (70) can be removed and the insertion structure (60) released
at the dislocation regions (80) of the radial extensions (64),
leaving only small implanted portions (96) of the radial
extensions, the external retention saddle (90) and related suture,
and the intact live-tissue anastomosis junction, as is shown in
FIG. 13F.
Referring to FIGS. 14A and 14B, synthetic-lumen (1) and live-lumen
(2) variations, respectively, of the inventive anastomosis device
are depicted with radial extensions (14, 64) restrained in an
upward configuration by a restraining member (102), the restraining
member (102) having a tension portion (101) configured to tear
through a perforated zone (103) of the restraining member (102)
upon application of a threshold tensile load, thus allowing the
restraining member (102) to be pulled upward and away, and allowing
the radial extensions (14, 64) to freely extend downward to their
unloaded state, as depicted in FIGS. 3A and 11A.
The synthetic lumen variation of the inventive device may also be
implanted in conjunction with a stent-like structural member, such
as an implantable flow device having a side port or T-graft, for
example, as described in the U.S. patent application for
"Implantable Flow Diversion Device", attorney docket number 3659-5,
incorporated by reference herein.
Each of the U.S. patent documents, U.S. patent application
documents, foreign patent documents, and scientific reference
documents (including texts and scientific journal articles)
referred to in the text of this document is incorporated by
reference into this document in its entirety.
Many alterations and modifications may be made by those of ordinary
skill in the art without departing from the spirit and scope of
this invention. The illustrated embodiments have been shown only
for purposes of clarity. These examples should not be taken as
limiting the invention defined by the following claims, said claims
including all equivalents now or later devised.
* * * * *